Sting is probably grateful that he still has hair. It has gotten much thinner than it used to be. I think it's pretty obvious that Sting and Andy are still "hitting the bottle." As for Stewart, I love his silver hair. It looks great on him. (Not to mention, it's shiny. I like shiny things. )
Quite honestly, the guys are older, and they've aged beautifully. I want to see them as they are today. I don't want to see them attempting to be themselves from 24 years ago. It's sad when musicians try to be something they aren't, and they are no longer the 30 year olds they used to be.
GG, I've not heard about iron helping to keep your hair dark, but I think it's supposed to help it stay strong. Problem with taking extra iron is that it can upset your stomach. I've heard of people with dark hair rinsing it with coffee water.